This invention relates to a street curb inlet filter, and more particularly to a street curb inlet filter for filtering out dirt and other contaminants from flowing into a street curb inlet.
Water flowing into a street curb drain carries erosion, leaves, grass clipping, floatable, and assorted trash into the drain, often clogging the storm sewer lines and allowing unwanted contamination into downstream creeks, rivers, lakes, aquifers, reservoirs, canals, or the sea. The environmental damage and financial costs of clean up from storm drains is enormous.
Debris and pollutants in runoff water are relatively heavy at construction sites, so sandbags are typically piled around a curb drain inlet as a filter. However, although sandbags block large debris, they impede water flow and do not effectively filter the flow.
Numerous solutions have been proposed to solve this problem. Straw wattles and hay bales have been used to filter out sediment and other solids flowing into a street curb inlet storm drain. Additionally, stones have been wrapped in chicken wire and placed in front of a street curb inlet type storm drain. The straw wattle and hay bail type of sediment filters often get clogged and are often not reusable. Also, they may decompose and slip into the storm drain. This could cause further clogging. Furthermore, the method using stones and chicken wire (stone bundles) does not filter out as large amount of sediment and other solids as do other methods. Also, these stone bundles break and fall into the drains, and can also be a safety hazard for children.
More sophisticated street curb inlet filter shave been proposed. Fleischmann (U.S. Pat. No. 6,974,540) describes a curb drain filter comprised of U-shaped brackets for attaching to an inside wall of a street curb drain adjacent an inlet. This approach has an internal supported debris basin with a filter media pack to collect debris. Kelly (U.S. Pat. No. 7,357,861) describes a street curb inlet filter with a filter body which includes a, substantially rigid, elongated frame and an elongated filter cover formed around at least one of the sides of the frame, wherein the filter cover is formed of a filtration material to filter out sediments and the like. Hurst (U.S. Pat. No. 7,438,802) describes a storm drain filter that includes a filter panel with a frame that holds a bristle filter in a configuration to filter incoming drainage water. The bristle filter includes a plurality of bristles arranged approximately perpendicular to the street surface. The bristles are arranged closely together to filter sediment from drainage water. The assembly protrudes partially out of the inlet and thus needs to be rotated out of the way during street cleaning.
These prior art attempts have often not been adopted by municipalities primarily because of their complexity, degree of difficulty in installation, their need for ongoing maintenance, and in some cases the difficulty of street cleaning unless the inlet protection device is first removed.
What is needed then is a more rigorous and easier to install and use inlet protection device, that effectively filters all of the drain water, is relatively hidden from view and does not require frequent maintenance nor removal for street cleaning.